Interpretive Summary: We have developed a method to follow the progress of food-grade starter cultures in laboratory sauerkraut fermentations. To do this we used a DNA fingerprinting method to analyze isolated cultures from these fermentations to determine which strains of the bacteria were present. The results of these studies were confirmed using genetically marked cultures, which are not food-grade. We found that selected starter cultures can predominate in the fermentation during the first week, after which other naturally present bacteria will continue the fermentation normally. The research was carried out as part of a larger project to develop controlled (with starter cultures) low salt fermentations for the vegetable fermentation industry. This is important because the disposal of waste salt is a significant ecological and economic problem for the vegetable fermentation industry. Further work will use this technology during scale-up to commercial fermentations.

Technical Abstract:
DNA fingerprinting methods were used to follow the progress of unmarked starter cultures in laboratory (1.2 and 13 L) sauerkraut fermentations. Random prime PCR (RAPD-PCR) was used for strain specific identification of Leuconostoc mesenteroides cultures. A comparative analysis of RAPD banding patterns for fermentation isolates and starter cultures was carried out using both genetically marked and unmarked cultures. While some variation in the RAPD patterns was observed, the results showed that the starter cultures dominated the fermentation during early heterofermentative stage for up to 5 days after the start of fermentation. Results from marked and unmarked starter cultures were confirmed by intergenic transcribed spacer (ITS)-PCR, and strain identify was confirmed by pulse field gel electrophoresis of chromosomal DNA digest patterns. The results demonstrate the utility of RAPD to follow the progress of unmarked starter cultures of L. mesenteroides in sauerkraut fermentations.